Superheater for water-tube boilers



July 20 1926.

A. COTTON SUPERHEATER FOR WATER TUBE BOILERS Filed June 6. 1921 INVENTOR ALFRED COT ATTORNEYS Patented July 20, 1926.

p UNITED STATES PATENT OFFICE.

ALFRED COTTON, OF ST. LOUIS, MISSOURI, ASSIGNO-R TOHEINE BOILER COMPANY,

OF ST. LOUIS, MISSOURI, A CORPORATION OF MISSOURI.

SUPERHEATER FOR WATER-TUBE BOILERS.

Application filed June 6, 1921. Serial No. 475,332.

This invention relates to water tube boilers of the upright, bent tube type that are pro vided with a superheater.

The main object of my present invention is to provide a highly. efficient steam superheater of simple design that can be applied easily andat a low cost to various makes of water tube boilers of the upright tube type.

To this end I have devised a steam superheater that comprises a superheater of any preferred design and a chamber for said superheater arranged at the front side of the boiler out of the main flow of the gases, but in such a way that a sufficient flow of gases through said superheater chamber is maintained to give the desired amount of superheat. The main walls of said superheater chamber are preferably supported by some of the water tubes that form part of the regular water circulating system of the boiler, and the gas inlet and exit of said chamber are so arranged that gases will enter said superheater chamber from the combustion chamber of the boiler, circulate downwardly over the superheater and then return to the combustion chamber. Preferably some of the water tubes of the boiler are arranged inside of the superheater chamber so as to cause the gases which enter said superheater chamber to cool rapidly and bevention is applicable to various other makes of water tube boilers of the upright tube t e.

lfteferring to the drawings which illustrate the preferred form of my invention, A, B and C designate a front, middle and rear steam-and-water drum, D designates a mud drum and 1, 2, 3 and 4i designate four banks of upright water tubes that are combined with said drums so as to form the water circulatory system of the. boiler. The. boiler is equipped with a superheater E which may be of any preferred design ,or construction,

and also with a chamber F that forms a passageway for gases which circulate over said superheater, the novelty of my present invention consisting 111 the arrangement of said superheater chamber and in the way the gases are caused to circulate through said chamber.

The location of the superheater chamber F will depend upon the particular type of boiler in which the superheater is installed but it is essential that the superheater chamber be located at the front side of the boiler in close proximity to the combustion chamber of the boiler and provided at its upper end with an inlet 00, in direct communication with the combustion chamber, through which the hot gases can enter from the combustion chamber and provided at its lower end with an exit y, in direct communication with the combustion chamber, through which the cool gases can return to the combustion chamber. It is also essential that the inlet 00 of the superheater chamber be located at a point below the first constriction in the main path of the gases flowing upwardly through the combustion chamber so as to ensure the suction in the main gas path at the exit 3 being as greatas the suction at the inlet 00 of the superheater chamber to insure a down draft through the superheater chamber. In the form of my invention herein illustrated this is accomplished by arranging the inlet a; of the superheater chamber in the front wall of said chamber at a point below a member 5 that forms the'top of the superheater chamber and whose front edge co-operates with the front wall of the combustion chamber G to form the first constriction in the main path of the upwardly flowing gases in the combustion chamber. It is preferable that the superheater chamber be arranged in such a manner that the front wall of same is supported by some of the tubes at the front of the boiler. In a four bank boiler of the kind herein illustrated the superheater chamber F is arranged between the radiant heat bank 1 and the convected heat bank 2, and the top wall 5 of said superheater chamber is spaced far enough below the front and middle drums A and B to form a passage way for the gases that escape from the combustion chamber, as indicated by the single headed arrows in the drawing, the front wall 6 of the superheater chamber being supported by the rear transverse row of tubes of the radiant heat bank 1 and the rear wall 7 of'said superh ater chamber being supported by atransverse row of tubes, preferably the front row of the COHTCC'I'LGd heat bani;

When the rear wall 7 of the superheater chamber is supported in this manner, some of the water tubes of the conveeted heat bank 2 will be located within the superheater chamber F. Accordingly, the hot gases which enter the upper end of the superheatcr chamber from the combustion chamber will cool rapidly upon coming in contact with the water tubes in the superheater chamber and will become of much greater density than the hot gases in the combustion chamber G of the boiler. If; siphon or negative chimney ef ect is thereby produced which causes a Vigorous down draft or current of hot gases through the superheater chamber. The superheater within the superheater chamber is therefore exposed to arapid flow of hot gases that have entered the vupper end of said chamber from the combustion chamber, and which, after circulating over the superheater, return to the combustion chamber through the exit g at the lower end of the super heater chamber. Preferably, a damper 8 is arranged at the lower end of the superheater chamber so as to control the return of the cool gases to the combustion chamber, and thus make it possible to accurately regulate the degree of superheat attained.

Having thus described my invention, what I c aim as new and desire to secure by Letters Patent is:

1. A water tube boiler of the upright tube type provided with a superheater chamber arranged between some of the water tubes at the front side of the boiler that form part of the regular water circulatory path of the boiler and located in close proximity to the combustion chamber, a top wall at the upper end of the superheater chamber that separates said chamber from the passagewa'y through which gases escape from the combustion chamber, a gas inlet at the upper end of said superheater chamber and a gas exit at the lower end of said superheate er chamber that establish direct communication between said superheater chamber and the combustion chamber, said gasinlet and gas exit being so disposed that the upward flow of the gases in the combustion chamber produces a suction at said gas exit in a direction to cause some of the gases to enter the superheater chamber from the combustion chamber, flow downwardly through same and then return to the combustion chamber, and a superheater arranged in said superheater chamber.

2. A water tube boiler of the u right tube type provided with a super eater chamber arranged between some of the water tubes at the front side of the boiler that form part of the regular water circulatory path of the boiler and located in close proximity to the combustion chamber, a top wall at the upper end of the superheater chamber that separates said chamber from the passageway through which gases escape from the combustion chamber, a gas inlet at the upper end of said superheater chamber and a exit at the lower end of said superheater chamber that establish direct communication between said superheater chamber and the combustion chamber, said gas inlet and gas exit being so disposed that the upward flow of the gases in the combustion chamber produces a suction at said gas exit in a direction toeause some of the gases to enter the superheater chamber from the combustion chamber, flow downwardly through same and then return to the combustion chamber, a superheater arranged in said superheater chamber, and water tubes in said superheater chamber separate and distinct from said superheater for cooling the gases so as to cause a rapid down draft over the superheater.

A water tube boiler of the upright tube type provided with a combustion chamber that has a constriction adjacent the upper end of same, a superheater chamber arranged between some of the water tubes at the front side of the boiler that form part of the regular water circulatory path of the boiler, a top wall at the upper end of the superheater chamber that separates said chamber from the passageway through which gases escape from the combustion chamber, a gas inlet in the front wall of said superheater chamber arranged below the constriction at the upper end of the combustion chamber, a gas exit at the lower end of said superheater chamber disposed so that the upward flow of the gases in the combustion chamber creates a suction at said exit in a direction to cause gases to enter said superheater chamber and flow downwardly through same, a superheater in said super-heater chamber, and water tubes in said superheater chamber that cool the gases and cause a rapid down draft over said superheater.

a. A water tube boiler of the upright tube type provided at its front side with a superheater chamber, a top wall at the upper end of the superheater chamber that separates said chamber from the passageway through which gases escape from the combustion chamber, walls at the front and rear of the superheater chamber supported by some of the water tubes of the boiler that form part of the regular water circulatory path, a super-heater in said superheater chamber, and a gas inlet and gas exit at the upper and lower ends of the superheater chamber, respectively, disposed so that the upward flow of the gases in the combustion chamber causes gases to pass from the combustion chamber into the superheater chamber through said inlet, then flow downward ly through said superheater chamber and thereafter return to the combustion cham her.

5. A water tube boiler of the upright tube type, comprising a radiant heat bank of water tubes, a convected heat bank of water tubes, a superheater chamber arranged between said banks, a wall at the upper end of the superheater chamber that separates said chamber from the passageway through which gases escape from the combustion chamber, a superheater in said superheater chamber, and means for utilizing the upward flowv of the gases in the combustion chamber to cause some of the gases in the combustion chamber to enter the upper end of said superheater chamber,

flow downwardly through same and then return to the combustion chamber.

6. A Water tube boiler of the upright tube type, comprising a radiant heat bank of water tubes, a convected heat bank of water tubes, a superheater chamber arranged between said banks, a wall at the upper end of the superheater chamber that separates said chamber from the passageway through which gases escape from the combustion chamber, a superheater in said superheater chamber, means for utilizing the upward flow of the gases in the combustion chamber to cause some of the gases in the combustion chamber to enter the upper end of said superheater chamber, flow donwardly through same and then return to the combustion chamber, and water tubes arranged inside of the superheater chamber for cooling the gases in said chamber and causing a rapid down draft over the superheater.

ALFRED COTTON. 

